A fingerprint sensor may generally include a chip assembly and a protection assembly. The protection assembly can protect the chip assembly, and increase the rigidity of the chip assembly, so that it is convenient to mount the fingerprint sensor in the terminal. The chip assembly may include an outer surface and an inner surface. The outer surface is exposed outside of the terminal, so that the outer surface can be touched. The protection element generally covers the outer surface or the inner surface, which may increase the thickness of the fingerprint sensor, so that the fingerprint sensor may not be suitable for a thin terminal.